BACKGROUND OF THE INVENTION
[0001] The present invention is directed to bicycle control cables and, more particularly,
to devices for sealing such control cables from deterioration as a result of the penetration
of foreign objects such as muddy water.
[0002] Control cables for controlling brakes and shift levers in a bicycle generally comprise
an inner cable slidingly disposed within an outer casing. Inner cables are made by
twisting several steel wires together. Outer casings commonly consist of a synthetic
resin liner that slides on the outer circumferential surface of the inner cable, a
band steel sheet spirally wound around the liner, and a synthetic resin jacket covering
the circumference of the band steel sheet. A gap to facilitate inner cable slip is
provided between the circumferential surface of the inner cable and the inside diameter
of the liner. Unfortunately, foreign objects and muddy water may penetrate from the
end of the cable into the gap and increase the sliding resistance between the inner
cable and housing, resulting in poor operating performance. Also, foreign objects
such as clay and sand in the muddy water also act as grinding materials and promote
wear in the liner and inner cable. Thus, such contamination should be prevented as
much as possible.
SUMMARY OF THE INVENTION
[0003] The present invention is directed to an apparatus for sealing a bicycle control cable
of the type wherein an inner cable is slidingly disposed within an outer casing so
that foreign objects do not penetrate between the cable housing and the cable. The
apparatus is simple, lightweight, and can be added to existing control cables.
[0004] In one embodiment of the present invention, a cap is provided for fitting over the
control cable. The cap includes first and second portions. The first portion has a
first inner surface defining a first inner hole, the first inner hole having a diameter
greater than an outside diameter of the inner cable and smaller than an inside diameter
of the casing. The second portion has a second inner surface defining a second inner
hole, the second inner hole having a diameter capable of receiving an end of the casing.
The first inner hole is sized to help prevent the penetration of foreign objects into
the control cable.
[0005] Many embodiments of such a cap are possible. For example, the first portion may comprise
essentially an end face of the cap, or it may comprise an elongated portion of the
cap. The thickness of the cap may be adjusted to allow the cap to bend with the cable.
The cap may include a reservoir space disposed between the first inner hole and the
second inner hole for allowing the accumulation of contaminants without entering the
remaining portions of the cable, or a seal space may be formed the same general location
to accommodate a seal. Other portions of the cap may be sealed as well. The inner
hole may include a liner to help reduce friction between the cable and the cap, or
else a liner already disposed within the control cable housing may include a liner
extension passing through the first inner hole. The cap may be used as an adjustment
component for the cable by providing a threaded portion which threads into a shift
control device or some other component The caps may be fastened to an existing bicycle
control cable system having an exposed portion of the inner cable between first and
second segments of the casing. In this case a cap is fastened to each segment of the
casing, and a cable cover is sealingly connected to the first cap. The cable cover
may cover the entire portion of the inner cable, or only a portion depending upon
the application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006]
Figure 1 is a cross sectional view of a particular embodiment of cap according to
the present invention for sealing a bicycle control cable;
Figure 2 is an exploded view of a particular embodiment of a cable adjusting barrel
unit of a shifting device;
Figure 3 is an enlarged cross sectional view of the cap shown in Figure 1;
Figure 4 is an enlarged cross sectional view of a another embodiment of a cap according
to the present invention;
Figure 5 is an enlarged cross sectional view of another embodiment of a cap according
to the present invention;
Figure 6 is an enlarged cross sectional view of a particular embodiment of a seal
component according to the present invention for the large diameter component of a
cap according to the present invention;
Figure 7 is an enlarged cross sectional view of another embodiment of a cap according
to the present invention;
Figure 8 is an enlarged cross sectional view of another embodiment of an outer end
cap according to the present invention;
Figure 9 is an enlarged cross sectional view of another embodiment, in the form of
an adjusting bolt, according to the present invention;
Figure 10 illustrates an example of a cap according to the present invention used
in an intermediate position in a cable; and
Figures 11(A-D) are enlarged cross sectional views illustrating various methods of
using the apparatus according to the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0007] Figure 1 is a cross sectional view of a particular embodiment of an outer end cap
according to the present invention as attached to a bicycle cable. Figure 2 is an
exploded view showing an outer end cap according to the present invention attached
to the cable adjusting barrel unit of a shifting device, with a cable installed therein.
As shown in those figures, the outer end cap
2 accommodates the end of the bicycle cable
1. The outer end cap
2 is inserted into the cable adjusting barrel unit
4 of the shift operating device
3, and an inner cable
6 is slidably inserted into the outer casing
5 of the cable
1.
[0008] The adjusting bolt
7 of the cable adjusting barrel unit
4 is screwed into and secured in a shift operating device
3. A spline
7a is formed around the head of the adjusting bolt
7. This spline
7a is inserted into and engaged in a spline
9a formed in the inner hole in a cylindrical operating clamp
9. When the circumference of the operating clamp
9 is rotated, the adjusting bolt
7 is rotated and driven via the spline
9a and spline
7a. The adjusting bolt
7 is moved axially by this rotation, and relative movement is produced between the
inner cable
6 and the outer casing
5 to adjust the position. A coil spring
8 is inserted between the adjusting bolt
7 and the operating clamp
9, and this coil spring
8 presses the operating clamp
9 to the shift operating device
3.
[0009] The inner cable
6 is made of several steel wires twisted together. A synthetic resin liner
10 for slidably guiding the inner cable
6 is mounted along the circumferential surface of the inner hole of the outer casing
5 around the inner cable
6. The outside diameter of the inner cable
6 is designated D1, and the inside diameter of the inner hole of the liner
10 is designated D2. This inside diameter D2 is greater than the outside diameter D1,
thus producing a gap S between them. A band steel sheet
11 is spirally wrapped around the liner
10. The band steel sheet
11 is intended to enhance the strength of the cable
1 and to maintain flexibility. The outer circumference of the band steel sheet
11 is covered with a synthetic resin jacket
12. As a result, the outer casing
5 is composed of a liner
10, band steel sheet
11, and jacket
12.
[0010] Figure 3 is an enlarged cross section of the outer end cap. The outer end cap
2 is made entirely of a synthetic resin, comprising a small diameter component
15 that covers the inner cable
6 component and a large diameter component
16 that covers the outer casing
5. The small diameter component
15 has an outside diameter d1, and the large diameter component
16 has an outside diameter d2. The inside diameter of the small diameter component
15 is d3, and that of the large diameter component
16 is d4. The inside diameter d3 of the small diameter component
15 is greater than the outside diameter D1 of the inner cable
6 and is smaller than the inside diameter D2 of the inner hole of the liner
10, resulting in the following relation: D1 < d3 < D2.
[0011] In this embodiment, there is a gap with a spacing of at least 0.3 mm between the
outside diameter D1 of the inner cable
6 and the inside diameter d3 of the small diameter component
15. The gap (that is, (d3 - D1)) should be no more than about 3 to 5% of the outside
diameter D1 of the inner cable
6. The gap should be such that, when the inner cable
6 is bent, the part characterized by maximum curvature does not block the inner circumferential
surface of the inner hole
17 of the small diameter component
15; that is, the inner cable
6 slides smoothly.
[0012] The thickness of the small diameter component
15 is thinner than that of the large diameter component
16, so the small diameter component
15 readily bends with the bending of the inner cable
6. The outside diameter dl of the small diameter component
15 is also no more than ½ of the outside diameter D3 of the cable
1. In this embodiment, the dimensions are no more than 2 mm, because the outer end
cap
2 can be made with lighter weight, and the small diameter component bends more readily
with the bending of the inner cable
6, as described above.
[0013] The length of the inner hole
17 of the small component
15 is L1, and the length of the inner hole
18 of the large diameter component
16 is L2, where L1 > L2. This relation is generally L2 = L1 × 0.8. This is because making
the length L1 of the inner hole
17 of the small diameter component
15 as long as possible improves the water repellent effects. There should be sealing
effects even in the absence of these conditions, however. An end surface
19 is formed at the tip of the inner hole
18 of the large diameter component
16.
[0014] The end surface
19 is intended to protrude at the end surface of the cable
1, forming a right angle with the circumferential surface of the inner hole
18. A 15 degree chamfer component
21 is formed at one end of the inner hole
18. The chamfer component
21 is used to facilitate the insertion of the outer end cap
2 onto the cable
1. A groove
20 is formed on the outermost circumference of the chamfer component
21. The groove
20 is intended to make it difficult for the outer end cap
2 to slip when it is held with the fingers, but the absence of any such groove will
not adversely affect the functions of the outer end cap
2.
[0015] Figure 4 is an enlarged cross section of a second embodiment of the outer end cap
2. The second embodiment has essentially the same structure as that in the first embodiment,
but there are some differences. The same symbols are used for parts that are the same
as the structural parts in the first embodiment The description of these parts is
omitted.
[0016] A foreign object reservoir component
19a is formed between the inner hole
17 of the small diameter component
15 and the inner hole
18 of the large diameter component
16. The foreign object reservoir component
19a is intended to trap foreign objects such as rubber or mud that penetrate from the
tip of the small diameter component
15, thus preventing them from penetrating inside the cable
1. The inside diameter d5 of the reservoir component
19a is such that d3 < d5 < d4.
[0017] Figure 5 is an enlarged cross section of a third embodiment of the outer end cap.
The third embodiment has essentially the same structure as that in the first and second
embodiments, but there are some differences. The same symbols are used for parts that
are the same as the structural parts in the first embodiment. The description of these
parts is omitted.
[0018] A cylindrical seal space
22 is formed between the inner hole
17 of the small diameter component
15 and the inner hole
18 of the large diameter component
16. A rubber seal
23 is inserted into and secured in this seal space
22. The seal
23 is roughly cylindrical in shape so that it can be inserted into the seal space
22. Cylindrical countersinks
24 are provided at both end faces of the seal
23. An inner cable sliding hole
25 is formed between the countersinks
24.
[0019] The inside diameter d6 of the inner cable sliding hole
25 is smaller than the diameter of the outside diameter D1 of the inner cable
6, but the seal
23 is made of rubber and thus deforms, allowing the inner cable
6 to slide, so that muddy water and the like can be prevented from penetrating inside.
The seal
23 is secured in the inner hole
18 with a seal cap
26. No seal cap
26 need necessarily be provided. The end face of the outer casing
5 may be allowed to come into direct contact with the seal
23.
[0020] The seal
23 is intended to prevent muddy water from penetrating from the small diameter component
15 to the large diameter component
16, but as shown in Figure 6, a flange
27 may be formed, a seal
28 may be placed at the flange
27, and muddy water and the like may thus be prevented from penetrating from the large
diameter component The inside diameter d7 of the seal
28 at this time is smaller than the outside diameter D3 of the cable
1.
[0021] Figure 7 is an enlarged cross section of a fourth embodiment of the outer end cap.
The structure of the fourth embodiment differs from that of the first through third
embodiments. The first through third embodiments had a small diameter component
15, but this is not provided in the fourth embodiment In this embodiment, an inside
diameter d3 is formed at the end face
25 of the outer end cap
2. The inside diameter d3 is formed based on the same principles as in the first through
third embodiments, such that D1 < d3 < D2. The same symbols are used for parts that
are the same as the structural parts in the first embodiment. The description of their
function and structure is omitted.
[0022] Figure 8 is an enlarged cross section of a fifth embodiment of the bicycle cable.
In the first through fourth embodiments, the inside diameter D2 of the inner hole
of the liner
10 was fixed. The fifth embodiment shown in Figure 8 has a liner extended part
10a integrated with the liner
10. The inside diameter D4 of the inner hole
29 of the liner extended part
10a is such that inside diameter D2 > inside diameter D4, thus making it difficult for
foreign objects such as muddy water to penetrate from the liner extended part
10a. The outer end cap
2 in the fifth embodiment may be a conventional type with no small diameter component
[0023] Figure 9 is an enlarged cross section of a sixth embodiment of an adjusting bolt
for a bicycle cable. The sixth embodiment need not be provided with an outer end cap.
A liner
34 with good lubricity is integrated with the inside circumferential surface in the
inner hole of a screw component
33 of the adjusting bolt
30. The adjusting bolt
30 is made of copper, aluminum, engineering plastic, or the like. A synthetic resin
liner
34 with an inner hole
35 is integrally provided by a mechanical fixing method involving coating, injection
molding, charging, or the like in the adjusting bolt
30. The synthetic resin of the liner
34 should have good lubricity allowing the wire
6 to slide.
[0024] The inner hole
35 of the liner
34 has an inside diameter d8. The adjusting bolt
30 has an inner hole
36 with an inside diameter d9. One end of the outer casing
5 of the cable
1 is inserted into this inner hole
36. The diameter of this inside diameter d9 is the same as or slighly smaller than the
outside diameter D3 of the outer casing
5. An annular seal
32 is integrally provided on the head of the adjusting bolt
30. The annular seal
32 is intended to maintain air-tightness between the adjusting bolt
30 and the outer casing
5 of the cable
1, and has a diameter that is the same as or slightly smaller than the outside diameter
D3 of the outer casing
5.
[0025] The sixth embodiment of an adjusting bolt
30 does not need an outer casing cap and thus has the advantage of fewer parts. The
sixth embodiment of an adjusting bolt
30 has a liner
34 and an annular seal
32 but need not necessarily have this liner
34.
[0026] Figure 10 illustrates an example in which the outer end cap is used in an intermediate
position in a shifter or brake cable. Figure 11(a) is an enlarged cross section of
parts
a in Figure 10. Figures 11(b), (c), and (d) are other examples of use. When the overall
length of a bicycle cable for operating brakes, shifters, or the like is lengthy,
there is an increase in the resistance caused by friction between the exterior circumference
of the inner cable
6 and the inside circumferential surface of the liner
10, and substantial force is needed to operate it.
[0027] In one method that has been adopted, as shown in Figure 10, the linear component
between points
41 of the cable used to operate the brakes
40, for example, has no outer casing
5, leaving the inner cable
6 exposed. The outer end cap
2 pertaining to the present invention can be used for this intermediate part A pair
of cable receivers
43 and
43 are integrally provided on the side frame
42 of the bicycle. The cable receivers
43 have a cylindrical inner hole
44, with an end face
46 at one end of this inner hole
44.
[0028] A slit
45 is formed in the axial direction in the inner hole
44. The slit
45 is to be used when the cable
41 is assemble with the bicycle and is intended to have only the inner cable
6 pass through. The aforementioned outer end cap
2 is inserted into the inner hole
4 of the cable receiver
43, and only the small diameter component
15 is allowed to protrude from the end face
46. An outer end cap
2 is similarly inserted into the other cable receiver
43 opposite, and they are made to face each other.
[0029] A cable cover
47 that covers the outer circumference of the inner cable
6 is fitted and fixed around the small diameter components
15 of the outer end caps
2 and
2. The cable cover
47 is a transparent synthetic resin pipe. The cable cover
47 is not necessarily needed but it is intended to protect the inner cable
6 and to prevent foreign objects from penetrating inside the cable
41.
[0030] In the case of the example of use illustrated in Figure 11(a), the cable cover
47 cannot be fitted around the small diameter components
15 and
15 unless it is cut to a precise length. As shown in Figure 11(b), however, the cover
can be used without being able to be fitted around the small diameter components
15 of one of the outer end caps
2 when the cable cover
47 is short.
[0031] The example of the use of outer end caps shown in Figure 11(c) is of an example in
which a cable cover
48 with an outside diameter greater than that of the cable cover
47 is fitted around and connected to this cable cover
47. The example of use shown in Figure 11(d) shows the use of a corrugated cable cover
49. The corrugated shape can be stretched and compressed, thus allowing the length to
be easily adjusted.
[0032] As described in detail above, when an outer end cap
2 having a small diameter component
15 is used in the present invention, a cable cover
47 for the protection of the inner cable
6 can be readily secured anywhere.
[0033] While the above is a description of various embodiments of the present invention,
further modifications may be employed without departing from the spirit and scope
of the present invention. For example, liners such as
10 and
34 may be omitted, and the caps may assume many different shapes and have more or less
components as desired. Thus, the scope of the invention should not be limited by the
specific structures disclosed. Instead, the true scope of the invention should be
determined by the following claims. Of course, although labeling symbols are used
in the claims in order to facilitate reference to the figures, the present invention
is not intended to be limited to the constructions in the appended figures by such
labeling.
1. A cap for a bicycle control cable (1) of the type wherein an inner cable (6) is slidingly
disposed within an outer casing (5), the cap comprising:
a first portion having a first inner surface defining a first inner hole (17), the
first inner hole (17) having a diameter (d3) greater than an outside diameter (D1)
of the inner cable (6) and smaller than an inside diameter of the casing (5); and
a second portion having a second inner surface defining a second inner hole (18),
the second inner hole (18) having a diameter (d4) capable of receiving an end of the
casing (5).
2. A cap according to Claim 1, wherein the first portion comprises an elongated portion
(15) of the cap.
3. A cap according to Claim 2, wherein an axial length (L1) of the first inner surface
defining the first inner hole (17) is greater than an axial length (L2) of the second
inner surface defining the second inner hole (18).
4. A cap according to any preceding Claim, wherein a gap between the outer surface of
the inner cable (6) and the first inner surface is at least 0.3mm.
5. A cap according to any preceding Claim, wherein a gap between the outer surface of
the inner cable (6) and the first inner surface is less than from approximately 3%
to approximately 5% of the outside diameter (D1) of the inner cable (6).
6. A cap according to any preceding Claim, wherein a thickness between the first inner
surface and an outer surface of the first portion is smaller than the thickness between
the second inner surface and an outer surface of the second portion.
7. A cap according to any preceding Claim, wherein an outside diameter (d1) of the first
portion is less than approximately 50% of an outside diameter (D3) of the casing (5).
8. A cap according to Claim 1 wherein the first portion consists essentially of an end
face (25) of the cap.
9. A cap according to any preceding Claim, wherein a third inner surface of the cap (2)
defines a reservoir space having a diameter (d5) greater than the diameter (d3) of
the first inner hole (17) and smaller than a diameter (d4) of the second inner hole
(18).
10. A cap according to any of Claims 1 to 8, wherein the cap further comprises:
a third inner surface defining a seal space (22) between the first inner hole (17)
and the second inner hole (18); and
a seal (25) disposed within the seal space.
11. A cap according to Claim 10, wherein the seal is generally cylindrical in shape and
has an inner diameter (d6) less than the outside diameter (D1) of the inner cable
(6).
12. A cap according to Claim 11, wherein the seal has an outside diameter greater than
the diameter (d3) of the first inner hole and smaller than a diameter (d4) of the
second inner hole (18).
13. A cap according to any preceding Claim, wherein the control cable (1) is of the type
wherein a liner (10) is disposed between an outer surface of the inner cable (6) and
an inner surface of the casing (5), and further comprising a liner extension (10a)
extending from the liner (10), the liner extension (10a) having an inside diameter
(D4) less than an inside diameter (D2) of the liner (10).
14. A cap according to any preceding Claim further comprising:
an adjusting bolt (7) disposed over the first portion, the adjusting bolt (7) having
a threaded portion extending axially away from the second portion.
15. A cap according to Claim 14, further comprising an operating clamp (9) coupled to
the adjusting bolt (7) for rotating the adjusting bolt (7).
16. A cap according to any preceding Claim, wherein the control cable (1) is of the type
wherein a liner (10) is disposed between an outer surface of the inner cable (6) and
an inner surface of the casing (5), and wherein the first inner hole (17) has a diameter
(d3) smaller than an inside diameter (D2) of the liner (10).
17. A cap for a bicycle control cable (1) of the type wherein an inner cable (6) is slidingly
disposed within an outer casing (5), the cap comprising:
a first portion having a first inner surface defining a first inner hole;
a second portion having a second inner surface defining a second inner hole, the second
inner hole having a diameter capable of receiving an end of the casing (5); and
a liner (34) disposed along the first inner surface.
18. A cap according to Claim 17 wherein the first portion includes a threaded outside
surface.
19. A cap according to Claim 18 further comprising an operating clamp (9) coupled to the
cap for rotating the cap.
20. A cap according to any preceding Claim further comprising a seal (28; 32) disposed
in the second portion for surrounding the casing (5).
21. A cap according to Claim 20 wherein the seal (28) is generally cylindrical in shape
and has an inner diameter (d7) less than the diameter (d4) of the casing (5).
22. In a bicycle control cable of the type wherein an inner cable (6) is slidingly disposed
within an outer casing (5), and apparatus for sealing an exposed section of the inner
cable (6) located between a first segment of the outer casing (5) and a second segment
of the outer casing (5) comprising:
a first cap including:
a first portion having a first inner surface defining a first inner hole through which
the inner cable (6) passes;
a second portion having a second inner surface defining a second inner hole, the second
inner hole having a diameter capable of receiving an end of the first segment of the
casing (5);
a second cap including:
a first portion having a first inner surface defining a first inner hole through which
the inner cable (6) passes;
a second portion having a second inner surface defining a second inner hole, the second
inner hole having a diameter capable of receiving an end of the second segment of
the casing (5); and
a first cable cover sealingly connected to the first portion of the first cap and
extending over the exposed section of the inner cable (6) toward the second cap.
23. Apparatus according to Claim 22 wherein the first cable cover extends over the entire
exposed section of the inner cable and is sealingly connected to the first portion
of the second cap.
24. Apparatus according to Claim 22 wherein the first cable cover extends only partially
over the exposed section of the inner cable (6).
25. Apparatus according to any of Claims 22, 23 or 24 wherein the first cable cover has
a corrugated shape.
26. Apparatus according to Claim 24, further comprising a second cable cover sealingly
connected to the first portion of the second cap and extending over the exposed section
of the inner cable (6) toward the first cap.
27. Apparatus according to Claim 26 further comprising a third cable cover (48) sealingly
connected to the first cable cover and to the second cable cover around outer surfaces
of the first cable cover and the second cable cover.